Re: KH wg spring in mc turbo results

[Sachelle Babbar <sbabbar@iris.nyit.edu>]

You are right, the kh spring is mildly stiffer and has more of a unform
feel (compressing it by hand) than the mc spring. The mc spring is very
soft early and age doesn't help it any.

As far as being able to reduce engine power...With the mc spring and the
assistance of the cockpit adjustable wastegate, I found a technique that
allows me to limit max boost to ~1.1 bar by supplying high vacuum to the
top of the wg through the controller and then closing it. Effectively, you
have a lighter spring. I still have yet to try this on the kh spring, but
my feeling tells me it won't be as necessary becasue of the linear power
curve. 

Just drove the car on a study break a little while ago. Great feel.
Midrange power and torque are now controllable as opposed to being "all or
nothing". Helps on twisty sections of road while trying to correct
oversteer by adding throttle to **pull** the car through. A feel that I
loved on my old kh- could just pull the car straight by throttling it. I
can do it in this car, but it's very different.

I've resolved myself to thinking that how these cars are so similar, but
minute differences can really set them a complete world apart. i'd hate to
say it, but the more I think about it now, the more I miss my autobox kh
because of feel. It's all seat of the pants and not times. However, I'm
going to attempt to get close with the current car.

****************************************************************************
*Steve                                             Sachelle Babbar
*'87  5000CS Turbo 5spd 1.3-2.0 bar             <SBABBAR@IRIS.NYIT.EDU>
*Cockpit adjustable wastegate, AudiSport badge
*
*Disclaimer:"Any information contained herein is based purely on my own
*personal experience and may not necessarily reflect yours. Use caution as
*your results may vary from mine."
********************************************************************************
                                                                               



On Sat, 20 Nov 1999, Orin Eman wrote:

> > KH spring + MC engine. Wonderful match. There is more down low torque and
> > the power is useable. Stock, a mild in crease in boost, maybe .1-.2. Power
> > arrives earlier, but more progressive and incredibly controllable (I have
> > a fwd 5 speed). It's overall a torquier feeling engine and I actually have
> > what feels like power in the wg controller closed position. I've restored
> > the adjustability in the boost increase; I haven't seen 1.7 bar since my
> > old kh. Just goes straight from 1.5-1.9. I can execute many maneuvers that
> > I haven't been able to since my kh.
> 
> > Conversely, I feel that the lighter mc spring in the kh + the wastegate
> > controller would be a wonderful combination due to the engine's better off
> > Idle torque.
> 
> Perhaps...
> 
> I think what you are seeing is that the MC spring is less stiff
> and allows the wastegate to crack open early.
> 
> Put a 1.6 bar spring (Scott Mockry had some) in an MC and you'll
> see boost earlier - it's a very noticeable difference in my car.
> This can be seen _before_ the WOT switch engages, so it's not
> the computer control which I have set to 1.8 bar.
> 
> I'll have to do some runs with the data aquisition board on
> my car and see what boost I do get...
> 
> Orin.
> 
>